<style>
    .injected-text {
        margin-bottom: -25px;
        text-align: center;
    }

    .box {
        border-style: solid;
        border-color: black;
        border-width: 5px;
        text-align: center;
    }

    .yellow-box {
        background-color: yellow;
        padding: 20px 40px 20px 40px;
    }

    .red-box {
        background-color: red;
        margin: 20px 40px 20px 40px;
        padding: 1.5em;
    }

    .green-box {
        background-color: green;
        margin: 40px 20px 20px 40px;
    }
</style>
<h5 class="injected-text">margin</h5>

<div class="box yellow-box">
    <h5 class="box red-box">padding</h5>
    <h5 class="box green-box">padding</h5>
</div>